/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.net.ipv4;
import java.net.BindException;
import java.util.Iterator;
import java.util.LinkedList;
/**
* A list of IPv4ControlBlock's.
*
* @author Ewout Prangsma (epr@users.sourceforge.net)
*/
public abstract class IPv4ControlBlockList {
protected final LinkedList<IPv4ControlBlock> list = new LinkedList<IPv4ControlBlock>();
private int lastFreePort = IPv4Constants.IPPORT_RESERVED;
/**
* Lookup the best matching control block for the given parameters.
*
* @param fAddr
* @param fPort
* @param lAddr
* @param lPort
* @param allowWildcards
* @return Null if no match, the best matching Control Block otherwise.
*/
public IPv4ControlBlock lookup(IPv4Address fAddr, int fPort, IPv4Address lAddr, int lPort,
boolean allowWildcards) {
IPv4ControlBlock bestcb = null;
int bestmatch = Integer.MAX_VALUE;
for (IPv4ControlBlock cb : list) {
final int match = cb.match(fAddr, fPort, lAddr, lPort, allowWildcards);
if (match == 0) {
// Exact match
return cb;
} else if ((match >= 0) && (match < bestmatch)) {
bestmatch = match;
bestcb = cb;
}
}
return bestcb;
}
/**
* Create a binding for a local address & port.
*
* @param lAddr
* @param lPort
* @return The created binding
*/
public synchronized IPv4ControlBlock bind(IPv4Address lAddr, int lPort) throws BindException {
if (lPort != 0) {
// Specific local port
if (lookup(IPv4Address.ANY, 0, lAddr, lPort, true) != null) {
throw new BindException("Address already in use");
}
} else {
// Choose free port
lPort = lastFreePort;
do {
lPort++;
if ((lPort < IPv4Constants.IPPORT_RESERVED) ||
(lPort > IPv4Constants.IPPORT_USERRESERVED)) {
lPort = IPv4Constants.IPPORT_RESERVED;
}
} while (lookup(IPv4Address.ANY, 0, lAddr, lPort, true) != null);
lastFreePort = lPort;
}
final IPv4ControlBlock cb = createControlBlock(null);
cb.bind(lAddr, lPort);
list.add(cb);
return cb;
}
/**
* Create an implementation specific control block.
*
* @return The created control block
*/
protected abstract IPv4ControlBlock createControlBlock(IPv4ControlBlock parent);
/**
* Add a block to the list
* @param cb
*/
final synchronized void add(IPv4ControlBlock cb) {
list.add(cb);
}
/**
* Remove a block from the list
* @param cb
*/
final synchronized void remove(IPv4ControlBlock cb) {
list.remove(cb);
}
/**
* Create an iterator over all entries
* @return The iterator
*/
protected Iterator<IPv4ControlBlock> iterator() {
return list.iterator();
}
}